Shock absorber



Aug. V29, 1933.

L, H. DAVIS SHOCK AsoRBER Filed Nov. 20, 1931 Patented Aug. V29, 1933snoer:v4 `Ansomnza Lewis H. Davis, Dayton, Ohio, assignor to DelcoProducts' Corporation, Dayton, Ohio, a Corporation of DelawareApplication November1`20, 1931 L. i serial iN.` 576,289

s,v claims'. (C1. v 18s-8s) This invention relates to improvements inhydraulic shock absorbers and* particularly to improvements in the fluidow control device for such shock absorbers... 'i

It is among the objects of the present invention to provide a shockabsorber with a fluid flow control device which is adapted to establisha substantially free flow of uid in one direction and a restrictedflowin the other direction.

Further objects and advantages of thelpres'ent invention will beapparent. vfrom thefollowin'g description, reference being had to theaccom?- panying drawing wherein a preferred embodiment ofone form ofthe. presentinvention is clearly shown.

In the drawing:

Fig. 1 is a fragmentary side View of a vehicle chassis having a .shockabsorber embodying the` present invention applied thereto.

Fig. 2 is a perspective view ofthe intake valve portion or the improvediiuid ow control device. Fig. 3 is a longitudinalsectional view takenthrough the shock absorber showing the improved fluid ow device appliedtothe piston of the shock absorber. v i i Y f Fig. 4 is av fragmentarysectional view taken substantially on the line 4f4 of Fig. 3.

Fig. 5 is an enlarged, assembly view ofthe entire fluid flowcontrol'device. n

Referring to the drawing the numeral 20 designates the shock absorberAcomprisinga casing providing a cylinder 21. The ends 'of this cylinderare closed by cylinder head caps 22 and 23. `Within the cylinder thereis provided a piston 24 comprising two piston head portions l25 andr26which are held together by screw studs 27 and 28.V The adjacent ends ofthe piston head portions 25 and 26 are recessed to receive the piston 10actuator 29 which is rotatably supported in the casing of the shockabsorber and has one end extending outside the shock absorber to whichthe shock absorber operating arm 30 is attached. Wear pieces 31 arecarried by each piston head portion 25 and 26 these wear piecesbeingengaged by the actuator 29 as shown in Fig. 4.

The free end of the shock absorber operating arm 301s vswivelly securedto one end of a link 32 .the opposite end of said link being swivellyattached to a bracket 33v which is secured to `the axle 34 of thevehicle by a clampingmember 35. The axle 34 supports the vehicle springs36 which in turn support the vehicle frame 37. Each piston head portion25 and 26 has a pas- -forms the compression .chamberfll at the oppositetermed the spring rebound control chamberfor valve.` An opening 54 inthetubular portion 50 sage 39 which provides for the transfer of fluid fromone side of the' .piston to the other. Piston -head vportion' 25 formsthe compression chamber '40 in the cylinder while rpiston head portionA2,6

rend of the cylinder. -The compression chamber 4i) may be termed thespring 'compression control chamber, .because .it controls thecompression movements of vehicle springs 36.l Chamber 4'1 is thischambercontrols the rebound'movements of 95 vehicle Vsprings 36.

'Referring to Fig. 3 thepassage 3`9 of piston head portion is providedV,with an annular valve seat 45 which is engaged bythe intake valvecomprising'a ange 46 and a tubular` body portion `47. .'The ilange 46 of.this intake valve is yieldably urged into engagement withth'e valveseat 45 by spring 146 one end of. which'` engages 'the intake valvetheotherf` resting upon a ,ring 48 seated within agroiove49.withinfthepistor"1. The tubular portion` 47. of the intake valveslidablyl supports vthe .pressure release'r valve comprising the tubularbody portion 50 and the head portion 51 the latter being urged, againstthe flange` yft ' 46 of the intakevalve by `spring 147. one end of whichengages the disc valvethe other.y an abutment collar secured attheffouter end 'of the tubular body-portion50 of said pressure releaseofthe pressure release valve is normally'within the confines of the,tubular portion 47 of the intake valve and thus is normally closedby-said' intake valve.` y n j. l This valveopera'tes as followszf .henthe piston head portion V26,` 'moves toward the left as regards Figs. 1and 3, in response tolcom'pression movements ofsprings36,Y fluidfrom'fthe casing Will flowinto the passage' 39 against the' a'ng'' 46 ofthe intake valve and the head 51 of the pressure release valve thus'exerting pressure thereon to move the valve assembly away from the wvalve seat 45 against' the effect of kspring 146 whereby to establish asubstantially free ow of iluid into the spring rebound control chamber41. .I Upon reverse movement of the piston, that is, when the piston`moves toward the right Yin response to rebounding movements of thevehicle springs 36, flange 46 of the intake Valvewill seat tightly uponthe valve seat 45 and thus the fluid m5 i ow passing `the intake valveat this point will be stopped. Asv soon as the pressure upon ther fluidwithin the chamber 41 reaches a predetermined value, the pressurelrelease valve will be Hb moved relatively to the intake valve, thus thestructure of the piston head portion 26 in the fol- Y lowing manner; theintake valve has a tubular portion 57 similar to the tubular portion 4'7of the other valve mechanism. It has a flange 56 similar to the flange460i" the other valve mechanism, however, flange 56 is provided withspaced humps or raised portions 60 which engage the annular valve seat55 through the effect offspring 58 -urging the intake valve to the saidvalve seat.

By. providingthe raised portions 60 substantially long thin spaces 76are provided between the Valve andthe valve seat which spaces are neverclosed and which when the piston head portion 25 moves to exert pressureupon the iiuid within the chamber 40 will establish sheet-like sprays ofreyso stricted fluid flows from said chamber 40 into ithe passage 39without'movement of the valve flange M5f. v rThis fluid flow in a thinsheet-like spray substantially eliminates hissing or whistling noiseswhich are generally set up when a high pressure fluid flowjiscondensed.If the pressure within the chamber 40 becomes excessive so that itcannot properly be relieved by the fluid flow through spaces -when thepressure release valve 61` comparing withv the valve comprising portions50 and 5l is operated against the effect of its spring 158 to establisha flow of iluid through `it Yand its side opening as has been'describedin connection with the pressure releasev valve of piston head portion26.

` In the present inventionapplicant has provided an intake' valve whichis adapted to establish a free flow` of fluid in the shock absorber whenthe piston operates in one directioncand by virtue of the raisedportionsthis intake valve is adapted to establish an initial, restricted flow offluid as the piston operates in the opposite direction. The height ofthe raised or hump portions 60 may be varied to vary this vinitiallyrestricted flow.

While the form of embodiment of the present invention as hereindisclosed, constitutes'a preferre'd form, it is to be understoodAthatyother forms might be adopted, all coming Within the scope ofthe-claims which follow;r

I What is claimed is as follows: 1. A shock absorber having a cylinderyin which a piston is reciprocably supported, said pistonv having apassage providing for the transfer of fluid from one side of the pistonto the other; a

valve-seat in the piston; a valve mechanism adapted to control the flowof uid through said piston passage in both directions said valvemechanism comprising a disc valve having a tubularbody portion providedwith an outwardly extending flange yieldably urged against thevalve-seat, the surface of said flange engaging the valve-seat havingspaced humps kproviding spaces between the valve-flange and valve-seat;

and a pressure release valve slidably supported in v the tubular bodyportion of the disc valve.

2v. `A shock absorber having a cylinder in which a vpiston isreciprocably supported, said piston having a passage providing for thetransfer of fluid from one side of the piston to the other; a

l,valve-seat in the piston; and a valve mechanism adapted to control theflow of fluid through said piston in both directions said valvemechanism comprising an intake valve adapted to establish asubstantially free flow of uid through the piston passage in response tothe movement of the piston in one direction and also adaptedindependently' to establisha restricted flow of fluid through the pistonpassage in response to the movement of the piston in the oppositedirection and also comprising a valve carried by the intake valve andadapted to establish a restricted additional flow of fluid through thepiston passage in response to a predetermined fluid pressure caused bythe movement of the piston in said opposite direction.` Y. Y 4 3. Ashock absorber having a cylinder in which a piston is reciprocablysupported, said piston having a passage providing for `thetransfer ofuid from one side of the piston to the other; a valve-seat in thepiston; afvalve mechanism adapted to control the-flow of uid throughsaid piston passage in Vboth directions said valve mechanism comprisingan intake valve adapted to establish aflow of fluid through the pistonpassagesubstantially unrestricted in onedirection and restricted in theother direction, said l to establish restricted fluid flows through thepiston passage in the other direction. Y

LEWIS I-I. DAVIS.

